EA casts doubt on Leeds protection scheme

17 June 2009

The Environment Agency (EA) has cast doubt on Leeds City Council’s aspiration for upstream flood storage to reduce the height of flood defences proposed for the city.

The agency has, however, suggested that a ‘bypass channel’ could significantly reduce the height of defences in part of the city.

The EA agreed in February to study possible additional measures, as well as the proposed flood defences, which could involve walls or embankments of up to 4m in height within Leeds city centre.

Leeds currently has no formal flood defences, and in 2007, the city experienced three flooding incidents following severe rainfall.

The EA is consulting on the outline designs for defences along the River Aire, while studying if building a dam or a bypass channel or both would meet the cost-benefit criteria. The results will be presented to the city council in July.

But Martin Slater, the Leeds flood-alleviation development manager, told Surveyor that while the work was ongoing, upstream storage was ‘not looking like a viable option’. The city council’s executive acknowledged that measures to reduce the heights of city centre defences would be more expensive – £150M, rather than £100M for defences alone.

Mr Slater said, however, that the issue was not solely the total cost, given that private sector contributions could be sought, but the need for a strong cost-benefit case.

‘Under the rules we work to, we have to find the optimum solution.’

The EA’s modelling indicated that building a dam upstream would reduce the height of defences by only 60cm, saving £2-£3M.

By contrast, the option proposed by Arup, of building a channel while lowering weirs on the Aire, could reduce defence heights by one metre, he said, while providing ‘a terrific asset for the people of Leeds’. The channel would normally be a linear park.

The scheme, however, was ‘not without difficulties’. It relies on the East Leeds link road removing traffic from the Hunslet Road, allowing it to be converted from dual-carriageway to single-carriageway.

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